Real-time integratable isolated voltage monitoring unit of semiconductor power switch to improve power converter reliability

The reliability of power converters has become a major design concern especially for those mission-critical industrial and aerospace applications required to operate in a harsh environment. There is a need for real-time monitoring techniques that are capable of tracking health status to give an alert signal before a disastrous system failure and furthermore make the early failure prediction due to long-term wear-out possible. This paper presents a real-time isolated voltage monitoring unit (IVMU) that monitors on-state voltage of a semiconductor power switch accurately. It can be integrated with off-the-shelf power converter to perform real-time status monitoring. The design has been validated with double-pulse testing and on a H-bridge inverter that utilize SiC power switches.